Nema17 motors driving 1204 ballscrews ...that ok?

[GEOFFREY]

That spindle assembly looks really good and excellent value. I can't comment about the noise as I can't hear it!!!(only the cleaner). G.

[HankMcSpank]

That spindle assembly looks really good and excellent value. I can't comment about the noise as I can't hear it!!!(only the cleaner). G.

Ironically, having just bought asbo's 300W spindle (which is a surprisingly fine spindle type for the price) ....the one I've now just gone and bought afterwards (above) looks to have exactly the same driving motor on it - they are just gearing up the motor's RPM with the pulley (I note they quote the motor at 24V vs. "upto 48V" that the 300W spindle motor is normally spec'ed for - I guess the spindle that the motor is driving only has modest bearings & wouldn't cope well with RPM above 10,000RPM - actually, perversely, I'm hoping the spindle *doesn't* use ceramic bearings & therefore the spindle shaft might be groundable - is that a word?)

Re the noise...as someone who mainly mills PCBs, I'm a sucker for a quiet spindle, and yes it's very quiet, which is why I pulled the trigger so quickly (the seller had sold 4 & only had one left)...only last week, I was comtemplating water cooled spindles, but I'm pleased I didn't now...I really don't need the extra grunt (& complexity/weight) that it yields.

Is there space between the linear bearings? could always make a new block up so as not to ruin the existing.

It's all too easy to reason that most members on here are of a solid engineering background ilk...I'm not - really small children laugh loudly at my output (I often hear them muttering things like "FFS, that bloke should have used angular contact bearings on his Z axis"...I have no idea what they're going on about).

I'm a reluctaant CNC'er ...I potter along blindly, then hit a problem ...& spend way too long trying to find an inadequate solution! (whereas, I'd much rather be playing my guitar & gulping on a cool one)

[Swarfing]

LOL! Hank no inference from me on that score, firm believer in you can only do what you can only do :-)

[GEOFFREY]

LOL! Hank no inference from me on that score, firm believer in you can only do what you can only do :-)

My belief is that you can do anything if you really want to and are prepared to put time and effort into it. I will be 70 in august and would like to think that I learn something new every day. Probably left it to late to become a brain surgeon now, but I don't really want too!!! G.

[HankMcSpank]

My belief is that you can do anything if you really want to and are prepared to put time and effort into it. I will be 70 in august and would like to think that I learn something new every day. Probably left it to late to become a brain surgeon now, but I don't really want too!!! G.

I agree with the sentiment (I probably undersold myself under the influence of a caipirinha last night), but alas I'm not that literate when working with metal/engineering (I haven't got the chops to fall back on....electrons yes....metal no!)....but I agree when faced with a challenge, most folks can solve it *if* they are driven & really need a solution! (oh yeah....& *if* they hang on places like this where people are so gracious with their time & knowledge <---this afro icon bears no relevance, I just figured it'll likely never get an outing here, so used it!)

[Lee Roberts]

I posted the link to your new spindle on ebay in the wrong thread Hank.

I think the price is great for what you get and was thinking if you did need more than the 10k RPM, now you have the option of changing the DC motor and this maybe easier to do: ER11 Spindle for Sable-2015 / SPD-ER11

.Me

[Jonathan]

The efficiency of a ballscrew is typically over 90%, compared to maybe 30-40% for a threaded rod which relies on sliding friction, so you would expect a big increase in feedrate. The torque required to accelerate the ballscrew would be greater due to the increased diameter, however since the pitch is greater the required angular acceleration is actually less, so overall you'll be much better off with the ballscrew.
The main reason for ballscrews having higher efficiency is they rely on rolling friction, not static friction, so you may want to consider trying the method I demonstrated here, where the screw nut is replaced with a bearing at an angle resting on the threads. That converts the drive to mostly rolling friction, so the efficiency is greater, plus it's also easy to get very low backlash. It's a very cheap way of upgrading, but I'd still stick with ballscrews if you can fit them in due to the accuracy (among other things).

Perhaps by using timing belts and pulleys to drive the screws you could fit in bigger motors? You could also use a favorable ratio to get higher resolution for milling PCBs. Incidentally, what feedrate and spindle speed do you currently use?

£66+15 for that spindle seems a lot to me when compared to the cost of the small brushless motors and controllers from hobbyking. Granted they're not that quiet, but I'm sure you'd find ways round that. The substantially higher RPM should make up for that too, since you could cut the PCBs faster.